■2S  Bed  Bark.  uZu^"'"' 
Trvptic  enzyniosis  is  exceedingly  sensitive  to  temperature.  Tlie 
nction  of  trypsin  on  milk  increases  in  energy  from  0°  to  but  above 
this  point  there  is  a  rapid  fall,  the  action  being  finally  arrested  between 
75°  and  80°.  There  is  not,  as  with  disastase,  any  range  or  platform 
of  indifferent  temperature. 
The  following  tal)le  shows  the  enzemic  values  of  twelve  samples  of 
pancreatic  extract  prepared  with  single  glands  from  four  i)igs,  four 
oxen  and  four  sheep,  killed  for  the  market.  All  the  observations  were 
made  at  40°.    T>  stands  for  diastasic,  T  for  triptic  value  : 
I'ig.  Ox.  Shrci.. 
No.  1.  D^166  No.  5.  D  ^  8  T^64  No.   i).  5  T  12) 
JSTo.  2.  D=U)0  No.  (J.  D=10  T=50  No.  10.  J)=12  T  -  <S3 
No.  3.  D^lOO  T-=72  No.  7.  D  =  9  T=42  No.  11.  T)^44  T  -  ()4 
No.  4.  D^lOO  T^()4  No.  8.  D=13  T=:83  No.  12.  D-=4  T  ^-  28 
The  oscillations  in  the  two  enzymic  values  do  not  exhibit  any  regu- 
lar relation  to  each  other. 
The  most  appropriate  standard  of  temperature  for  the  valuation  of 
tryptic  activity  is  40°,  as  it  corresponds  very  nearly  with  the  tempera- 
ture at  which  trypsin  operates  in  the  normal  digestion  of  warm-blooded 
animals;  but  it  is  more  convenient  to  perform  tlie  testing  at  or  near 
the  ordinary  temperature  of  the  room,  say  at  20°;  and  the  author  has 
ascertained  that  the  values  of  T  obtained  at  this  temperature  may  be 
converted  with  sufficient  accuracy  into  the  corresponding  values  at  40° 
by  multiplying  them  by  '>"5. — Jonr.  Chern.  Soc,  Nov.,  1881;  Proc 
lioif.  Soc,  xxxii,  }>.  145. 
ON  RED  BARK. 
By  John  Eliot  Howard,  F.R.8.,  F.L.8. 
Read  before  British  Pharmaceutical  Conference. 
In  order  to  present  more  definitely  tlie  results  of  recent  information  oii 
this  subject,  together  with  some  suggestions  for  discussion  at  the  Confer- 
ence, I  must,  in  some  sense,  begin  at  the  beginning,  and  show  what  I  niean 
by  "red  bark." 
The  limitation  of  the  genus  Cinchona  to  those  plants  which  have  ca])- 
sules  dehiscent  from  the  l)ase  towards  the  apex  seems  to  me  most  correct 
and  natural.  I  think  my  friend.  Prof.  Karsten,  has  done  good  service  to 
(juinology,  not  only  by  the  magnificent  and  unique  plates  and  descriptions 
in  his  splendid  volumes  of  the  Cinchona  cordifolia  and  C.  lancifoHa  (for 
instance),  but  also  of  the  lesser  known  group  wliieli  he  includes,  to  my 
regret,  under  the  same  head  of  cinchonas  {Cinchona,  sectio  Heferasca). 
These  have  capsules  variously  dehiscent,  though  in  other  respects  closely 
